Disturbance and population dynamics of kelp forest communities

Historical data on giant kelp biomass

Long-term records of giant kelp biomass were obtained from ISP Alginates (formerly Kelco Co.). This company harvested giant kelp for >50 years and collected information on the abundance of giant kelp in California and Mexico from routine (~ monthly) aerial surveys from 1958 to 2005. A standard protocol was used by an observer in a small fixed-wing aircraft to visually estimate the harvestable tonnage of giant kelp biomass for 109 designated kelp beds. ISP Alginates provided us with copies of all of their archived records which we used to create a digital database on the historical abundance of giant kelp throughout its range in California and Mexico. This database is helping us evaluate long-term trends in the abundance of giant kelp and place our observations of kelp abundance within the Santa Barbara Channel into a much broader regional and temporal perspective. Kelp surveys by ISP Alginates were discontinued in 2005. We are working closely with former ISP Alginates scientists to continue aerial kelp surveys and maintain the database on giant kelp for southern California.